Abstract
BACKGROUND/AIMS: We aimed to investigate the comfort, safety, and endoscopic visibility during esophagogastroduodenoscopy (EGD) afforded by a modified 4-hour semifluid and 2-hour water ("4+2") fasting protocol. METHODS: In this parallel group, endoscopist-blinded, randomized controlled trial, outpatients undergoing unsedated diagnostic EGD from 10:30 AM to 12:00 PM were randomly assigned to either a "4+2" protocol group or a conventional fasting group. The participants' comfort during the fasting period and procedure was measured using the visual analog scale, and mucosal visibility was measured by endoscopists using the total visibility score. Satisfaction was defined as a visual analog scale score of ≤3. The primary outcome was the participants' comfort during fasting. RESULTS: One hundred and six and 108 participants were randomized to the "4+2" protocol and control groups, respectively. Participants' comfort before EGD was significantly higher in the "4+2" protocol group measured by both the proportion of satisfaction (86.8% vs 63.9%, p=0.002) and the visual analog scale score (median [interquartile range]: 1.0 [1.0-2.0] vs 3.0 [1.0-4.0], p<0.001). The proportion of satisfaction during EGD also significantly improved (59.4% vs 45.4%, p=0.039) in the "4+2" protocol group. The total visibility score was unaffected by the fasting protocol (5.0 [4.0-5.0] vs 4.0 [4.0-5.0], p=0.266). No adverse events were observed during the study. CONCLUSIONS: The "4+2" protocol was more comfortable and provided equal mucosal visibility and safety compared with conventional fasting for unsedated EGD.